March 19, the site will be in read only mode for 4 hours for a maintenance. If you are trying to ask a question and an article does not solve your issue, please find one of our partner sites for more help: @firefox, /r/firefox on reddit, and Mozillazine.org, we will have community standing by. Or live on our IRC channel - https://client02.chat.mibbit.com/?server=irc.mozilla.org channel #sumo

What are pop-ups?

Pop-up windows, or pop-ups, are windows that appear automatically without your permission. They vary in size but usually don't cover the whole screen. Some pop-ups open on top of the current Firefox window, while others appear underneath Firefox (pop-unders).

Firefox allows you to control both pop-ups and pop-unders through the Content panel in the OptionsPreferences
window. Pop-up blocking is turned on by default, so you don't have to worry about enabling it to prevent pop-ups from appearing in Firefox.

When blocking a pop-up, Firefox displays an information bar (if it hasn’t been previously dismissed – see below), as well as an icon in the location bar.

When you click either the OptionsPreferences button in the info bar or the icon in the location bar, a menu is displayed with the following choices:

Blocking pop-ups may interfere with some websites: Some websites, including some banking sites, use pop-ups for important features. Blocking all pop-ups disables such features. To allow specific websites to use pop-ups, while still blocking all others, you can add those specific websites to the list of allowed sites.

Blocking pop-ups doesn't always work: Although Firefox blocks most pop-ups, some websites may show pop-ups using uncovered methods, even when they are blocked.

Pop-up blocker settings

To access the pop-up blocker settings:

Click the menu button and choose Options.Preferences.

Select the Content panel.

In the Content panel below Pop-ups:

Uncheck the box next to Block pop-up windows to disable the pop-up blocker altogether.

A click on Exceptions… opens a dialog box with a list of sites that you want to allow to display pop-ups.

The dialog box offers you the following choices:

Allow: Click this to add a website to the exceptions list.

Remove Site: Click this to remove a website from the exceptions list.

Remove All Sites: Click this to remove all of the websites in the exceptions list.

Note: Blocking pop-ups may not always work and may interfere with some websites. For more information, see the What are Pop-ups? section above.

Pop-ups not being blocked

Is the pop-up coming from Firefox?

The pop-up may not actually be coming from Firefox. You can determine where the pop-up is coming from by the appearance of the window.

If you see the location bar with the Site Identity button (a globe, padlock or warning triangle)
button in the pop-up window, the pop-up is coming from Firefox.

Close the about:preferences page. Any changes you've made will automatically be saved.

Is the pop-up shown after a mouse click or a key press?

Certain events, such as clicking or pressing a key, can spawn pop-ups regardless of if the pop-up blocker is on. This is intentional, so that Firefox doesn't block pop-ups that websites need to work.

Is it a true pop-up window?

Sometimes ads are designed to look like windows, but really aren't. Firefox's pop-up blocker can't stop these ads.

Mozilla surveys

When you visit a Mozilla website, sometimes you'll see a pop-up asking you to participate in a survey. The only third-party that Mozilla ever uses for surveys is SurveyGizmo, which has been vetted by our legal and privacy teams. The Firefox pop-up blocker doesn't block these pop-ups.